RELATED APPLICATIONSThis application is a divisional of co-pending U.S. application Ser. No. 09/774,275, filed on Jan. 30, 2001, which is a divisional of U.S. application Ser. No. 09/474,493, filed Dec. 29, 1999,which is a continuation-in-part patent application of U.S. patent Parent application Ser. No. 09/431,732 filed on Nov. 1, 1999, which claims the benefit of prior provisional application Serial No. 60/133,810, filed on May 11, 1999.[0001]
BACKGROUND OF THE INVENTIONThe present invention relates generally to the field of reclosable bags and more specifically to reclosable bags that use or incorporate tamper evident, hermetic seal, and reclosable fastener assemblies or mechanisms of the slider or zipper type. The present invention is particularly concerned with a reclosable bag that may be filled with a food product at a factory or food processing plant and then sealed to protect the food product until such time as a customer purchases the reclosable bag and opens it to access the food product within.[0002]
Reclosable, typically flexible, containers are well known in the art. Such containers normally comprise a bag-like structure made from a folded web of material, like thermoplastic film. These types of containers may also include reclosable zipper structures, as well as interlocking male and female zipper elements fused, extruded, or attached to the bag sidewalls. Alternatively, the reclosable zipper structures, mechanisms, or assemblies may also be identified as slider closure systems, i.e., a closure system for slider bags and form, fill and seal technology that contain two tracks that can be interlocked and a separate part (a slider) that rides on the tracks and is used to open and/or close the tracks. The bag-like structure is created when the thermoplastic film is folded, sealed, and severed along its exposed edges.[0003]
Reclosable bags are a great convenience to the consumer. This is especially true where the food product or material contained within the bag is of a type that may not all be consumed at once, for example, shredded cheese, sliced cheese, cheese, processed cheese, deli meats, snack foods, vegetables, fruits, sweets, etc. A problem with these types of bags is achieving a design in which the food product is hermetically sealed against oxygen, atmospheric intrusion or transmission, bacteria, molds, and/or other sources of contamination, while also providing features that help to disclose to the consumer evidence of tampering without substantially interfering with the ease of use of the bag.[0004]
In addressing this problem it is also desired to achieve a design that is easy to manufacture and may be used in combination with known types of packaging machinery that use form, fill, and seal technology such as Horizontal Form Fill and Seal (HFFS) machines or Vertical Form Fill and Seal (VFFS) machines. It is also desired to achieve a design that may optionally be used in combination with Horizontal Flow Wrapper (HFW) machines; e.g., J-WRAP machines presently available from Jones Automation Company, Inc. of Beloit, Wis.[0005]
Tamper evident packaging may also require the use of several pieces of film, which must then be connected to each other. This can make manufacturing of the reclosable bag more complicated.[0006]
It is one of the objectives of the present invention to provide a reclosable bag that may be manufactured using known packaging machinery. As previously, noted, such known machinery includes HFFS machines, VFFS machines, and HFW machines. Additionally, as will be apparent to a person of skill in the art after reading the present disclosure contained herein thermoform type machines like the one disclosed in U.S. Pat. No. 4,240,241 could also be used to practice the present invention disclosed herein, after appropriate modification as the disclosure herein will make apparent.[0007]
It is also an objective to perform the manufacturing task using only one piece of parent film in combination with a reclosable zipper assembly.[0008]
Further, it is an objective of the invention to provide the manufacturer with the option of including some or all the features of tamper resistance or evidence, hermetic seal, and ease of use in the reclosable bag that is produced.[0009]
Another objective, especially with slider or zipper type structures or sliding type zippers or fasteners is ease of use. While a sliding type zipper structure is itself relatively easy to use, the bag structures include sidewalls or fin portions that extend up past the sliding type zipper, structure. This interferes with the consumer's access to the food, makes it difficult to see the zipper structure, and also makes it more difficult to easily operate the zipper mechanism. This is especially true if the person opening and closing the bag is disabled, has arthritis, or another aliment, which limits the manual dexterity of that person.[0010]
Additionally, increased ease of access to the food product is an objective because the larger the zipper structure and its associated elements the smaller the opening left to the consumer to access the food product.[0011]
The present invention is believed to address these and other objectives by the unique and simple structures and methods disclosed herein.[0012]
SUMMARY OF THE INVENTIONThe present invention may generally be described as a reclosable bag for filling with at least one food product. The reclosable bag includes at least one sheet of web material. The sheet of web material has at least two areas of structural weakness and at least one fold structure located between and defined by the two areas of structural weakness. The reclosable bag includes an opening located generally opposite the fold structure. (Please note that fold structure as used in the specification and claims herein is to be interpreted as broadly as possible and should include not only structures that are a fold but also any structure that has the same or similar characteristics to a fold even though said structure may be formed by non-folding means or methods such as the result of joining or fusing the edges of two or more sheets of film.) In addition, the reclosable bag includes a sliding fastener structure having a skirt structure of web material extending therefrom and located within the fold structure. The skirt structure or skirt material may be either integral to the slider fastener structure or it may be coupled, e.g., sealed or adhered, to the slider fastener structure. The skirt structure includes a distal margin that is coupled to the sheet of web material at a location between the areas of structural weakness and the opening. The web material of the reclosable fastener structure extending past the areas of structural weakness so that the reclosable fastener structure is located within the fold structure. The reclosable bag is capable of being filled with at least one food product through the opening.[0013]
The reclosable bag structure of the present invention may optionally include other features. For example, but not by way of limitation, the skirt may include an outside surface and an inside surface. The distal margin is located on the outside surface. The inside surface may include a predetermined area having a releasable adhesive material. This allows for the option of having a peelable seal, which may be used to aid in making the reclosable bag initially hermetic and may also add another reclosable/resealable feature to the bag. (Please note that the terms reclosable, resealable, and releasable, in addition to their normal meaning, are used herein, interchangeably, to describe a closed or sealed opening that may be re-opened at a predetermined time to aid in providing access to at least a portion of the contents of the bag, and then closed or sealed to allow the remaining contents to be stored in the bag for later use and/or provide evidence of tampering.)[0014]
Additionally, and more typically, the web material of the reclosable bag is substantially comprised of a predetermined portion of a roll of a parent film material. The predetermined portion having predetermined dimensions from which a reclosable bag of predetermined dimensions may be constructed. The parent film material may be manufactured to a specification which determines the shape and location of the areas of structural weakness and which makes the areas of structural weakness an integral part of the parent film. Presently, it is believed to be commercially preferred to do so. Alternatively, the areas of structural weakness could be applied to the parent film at a predetermined step of the construction or manufacturing process of the resealable bag.[0015]
Further, the areas of structural weakness may extend intermittently, continuously, and linearly, nonlinearly, or in some other predetermined pattern across a predetermined dimension of the sheet of web material. The predetermined dimension where the area of structural weakness is located may be either the length or the width of the reclosable bag, which is usually rectangular in shape, depending on whether or not it is desired to use the long edge or side of the bag or the short edge or side of the bag with the slider closure system. Use of the long edge of the bag provides for a larger opening and thus enhances the ease of access to the food material or other materials contained within the reclosable bag.[0016]
The term structural weakness is generally used to describe that area of the reclosable bag that is intentionally designed to be easily torn by the consumer to provide for evidence of tampering and to allow for easy exposure of the zipper mechanism or assembly. Nonetheless, it should be understood that use of the term structural weakness should include, without limiting its meaning, structures such as perforation, scores, microperforations, and multiple laminate materials which include a layer having an area of material or materials which are specifically designed to be easily torn. Accordingly, it should be understood that the areas of structural weakness are intentionally designed to create a predetermined tear path, which may or may not be hermetic.[0017]
Also, opening of the bag may be facilitated by the application of a tear strip (e.g., tear tape or tear string) along a predetermined surface or surfaces of the parent film. The tear strip may or may not be used in combination with a predetermined area of structural weakness.[0018]
Alternatively, the present invention may be described as a reclosable bag for filling with at least one food product and comprising at least one sheet of a web material. The sheet of web material includes a first area of structural weakness and a second area of structural weakness. (Alternatively, the areas of structural weakness may be tear areas or areas having a propensity to tear in a predetermined direction.) The sheet of web material including at least one fold structure, located between and defined by the first and second areas of structural weakness, and a fill opening. The sheet of web material further comprising a first panel coupled to the fold structure at the first area of structural weakness and a second panel coupled to the fold structure at the second area of structural weakness. A reclosable fastener structure including a male track structure and a female track structure. The male track structure including a first fin structure of web material extending therefrom and the female track structure including a second fin structure of web material extending therefrom. Each fin structure including a predetermined coupling portion. The coupling portion of the first fin structure being coupled to the first panel and the coupling portion of the second fin structure being coupled to the second panel. (please note that the seal, when it is formed, may be adjacent or near but should not be on the area of structural weakness). The reclosable fastener structure extending past the areas of structural weakness and into the fold structure. The areas of structural weakness being located below the reclosable fastener structure. The alternative reclosable bags are also capable of being filled with at least one food product through the fill opening, which is subsequently sealed.[0019]
The present invention allows the fold structure to be easily removed from the reclosable bag. More importantly the present invention allows the consumer to substantially expose the reclosable fastener structure so that it is easily accessible and the consumer does not have to be impeded by bag sidewalls or bag fin portions that extend up past the zipper structure. Finally, the present invention accomplishes this using but not limited to substantially one piece of film material.[0020]
Alternatively, the present invention may be described as a reclosable bag for filling with at least one food product. The reclosable bag may include at least one sheet of web material, at least one tear tape structure, at least one fold structure, and an opening located generally opposite the fold structure. A reclosable fastener structure including at least one integral skirt structure of skirt web material extending therefrom. The integral skirt structure including at least one distal margin. The distal margin being coupled to the web material at, at least one location between the tear tape structure and the opening. The reclosable fastener structure extending past the tear tape structure and into the fold structure. The reclosable bag capable of being filled with at least one food product.[0021]
Additionally, the reclosable bag for filling with at least one food product, may also be described as a reclosable bag including at least one sheet of web material having at least one fold structure presenting at least two sidewall structures having inside surfaces, and an opening located generally opposite the fold structure. A reclosable fastener structure including an integral skirt structure comprising a web material extending therefrom and including opposed distal margin structures. The web material of the integral skirt structure being sealed to the inside surfaces of the sidewall structures at a plurality of predetermined sealing areas. The reclosable bag may also include a barrier web material extending between and coupled to the distal margin structures.[0022]
The barrier web material of the alternative bag may alternatively extend between and be coupled to the sidewall structures. Alternatively, the barrier web material may also be coupled to predetermined sealing areas by at least one peelable seal. Alternatively, the barrier web material may include at least one area of structural weakness that extends through it along a direction generally parallel to the predetermined sealing areas.[0023]
Alternatively, the reclosable bag for filling with at least one food product of the present invention may include at least one sheet of web material having at least one predetermined tear area, at least one fold structure, and an opening located generally opposite the fold structure. A reclosable fastener structure including at least one integral skirt structure of skirt web material extending therefrom. The integral skirt structure including at least one distal margin. The distal margin being coupled to the web material at, at least one location between the tear area and the opening. The reclosable fastener structure extending past the tear area and into the fold structure. The reclosable bag capable of being filled with at least one food product.[0024]
This alternative reclosable bag structure may further include at least one piece of a header material located in a predetermined area of the fold structure. The header material may include at least one edge structure adjacent the tear area. The reclosable bag of this alternative structure may further include at least one tear tape structure coupled to the web material and adjacent to the tear area.[0025]
Alternatively, the present invention may be described as a reclosable bag for filling with at least one food product. The reclosable bag may include at least one sheet of web material, at least one tear tape structure, at least one fold structure, and an opening. A reclosable fastener structure including at least one integral skirt structure of skirt web material extending therefrom. The integral skirt structure including at least one distal margin. The distal margin being coupled to the web material at, at least one location between the tear tape structure and the opening. The reclosable fastener structure extending past the tear tape structure and around and over the fold structure. The reclosable bag capable of being filled with at least one food product.[0026]
Additionally, the reclosable bag for filling with at least one food product, may also be described as a reclosable bag including at least one sheet of web material having at least one fold structure, and an opening. A reclosable fastener structure including an integral skirt structure comprising a web material extending therefrom and including opposed distal margin structures. The web material of the integral skirt structure being sealed to the outside surfaces of the sidewall structures at a plurality of predetermined sealing areas. The inside surface of the reclosable bag may also include a predetermined area having a releasable adhesive material. This allows for the option of having a peelable seal, which may be used to aid in making the bag initially hermetic and may also add another reclosable/resealable feature to the bag.[0027]
Additionally, the present invention may be described as a method of construction using known form-fill-and-seal machinery including but not limited to HFFS, VFFS, and HFW machines. The steps of the method of construction include 1. Folding the sheet of web material along a predetermined folding area located between the areas of structural weakness to form the fold structure. 2. Inserting the reclosable fastener into the fold structure. 3. Coupling the distal margin of the integral skirt structure to the web material. 4. Sealing the web material along at least two predetermined linear areas located generally perpendicular to the fold structure. 5. Filling the reclosable bag with at least one food product through an opening. 6. Sealing the opening. Please note that in an HFW application it is presently believed that the step four should occur last.[0028]
The method may also include a step of inserting either a tear tape or a tear string at least prior to step four. Further, a header strip could also be introduced prior to step four.[0029]
Alternatively, the web material may be slit along the fold line and the reclosable fastener assembly inserted and sealed to result in an exposed zipper structure assembly at one end of the bag.[0030]
Also, alternatively, if the reclosable bag is designed to have a gusset opposite the zipper opening then the fill opening may be sealed and the bag may be filled with product through the zipper opening.[0031]
Alternatively, the process and structure of the present invention could include a reclosable fastener assembly having two skirts or flaps of web material. The first skirt could be coupled or sealed to the parent film prior to folding the parent film. (Additionally, the first skirt could be tack or partially sealed prior to folding and then subsequently a full seal applied in the HFFS, VFFS, or HFW machine.) After folding the parent film the second skirt or flap would be sealed to the film sidewall located opposite the sidewall to which the first skirt is sealed or coupled. Construction of the bag could then be completed as disclosed herein.[0032]
DESCRIPTION OF THE DRAWINGSFIG. 1 is a top plan view of a predetermined portion of parent film comprising a sheet of web material including at least two areas of structural weakness.[0033]
FIG. 2 is an edge elevational view of a portion of the sheet of web material of FIG. 1 and shows the location of the areas of structural weakness.[0034]
FIG. 3 is a side elevational view of the fold structure of a reclosable bag of the present invention showing the position of the slider or zipper structure in the fold structure relative to the predetermined position of the areas of structural weakness.[0035]
FIG. 4 is a perspective view of the embodiment shown in FIG. 3.[0036]
FIG. 5 is a front plan view of a first embodiment of the present invention.[0037]
FIG. 6 is a front plan view of an alternative to the first embodiment of the present invention disclosing sealed[0038]track mass23b.
FIG. 7 is a front plan view of an alternative embodiment of the present invention.[0039]
FIG. 8 is a view taken from[0040]line8--8 of FIGS. 5 and 6.
FIG. 9 is an alternative to the embodiment of the present invention shown in FIG. 8.[0041]
FIG. 10 is another alternative to the embodiment shown in FIG. 8.[0042]
FIG. 11 is an alternative to the embodiment shown in FIG. 10 wherein a peal seal tape with a releasable adhesive located on one side of the tape is used.[0043]
FIG. 12 is a view from line[0044]12-12 of FIG. 11, theheader material15 that is shown, along with other structures, is optional.
FIG. 13 is another alternative to the embodiment shown in FIG. 8.[0045]
FIG. 14 is a front plan view of another alternative embodiment of the present invention.[0046]
FIG. 15 is a view taken from[0047]line15--15 of FIG. 14.
FIG. 16 is an alternative to the embodiment of the present invention shown in FIG. 15.[0048]
FIG. 17 is another alternative to the embodiment shown in FIG. 15.[0049]
FIG. 18 is another alternative to the embodiment shown in FIG. 15.[0050]
FIG. 19 is a front plan view of an alternative embodiment of the present invention.[0051]
FIG. 20 is a view from[0052]line20--20 of FIG. 19.
FIG. 21 is a plan view of an alternative embodiment of the present invention illustrating various features of the invention including die cutting of the track mass of the zipper assembly and the use of a tear structure like a tear tape or a tear string.[0053]
FIG. 22 is a view from[0054]line22--22 of FIG. 21.
FIG. 23 is a view of an alternative to the embodiment shown in FIG. 22 wherein tear tape is applied to both the inside and outside surface of the bag.[0055]
FIG. 24 is a cut-away view of an alternative to the embodiment shown in FIG. 22 wherein the tear tape includes a tear bead.[0056]
FIG. 25 is a perspective view of the embodiment shown in FIG. 24.[0057]
FIG. 26 is a cut-away view of a predetermined portion of the embodiment shown in FIG. 24 illustrating the tear tape and tear bead's relationship to the film and the area of structural weakness created as a result of the presence of the tear bead.[0058]
FIG. 27 is an alternative embodiment to the structure disclosed in FIG. 22.[0059]
FIG. 28 is a plan view of an alternative embodiment of the present invention illustrating various features of the invention including the use of an optional header strip and the use of an optional opening to assist in removal of the hood and exposure of the zipper assembly.[0060]
FIG. 29 is a view from[0061]line29--29 of FIG. 28.
FIG. 30 is a schematic diagram showing the components of another alternative embodiment of the present invention being fed into a machine suitable for adaptation to perform the process and make at least one of the products disclosed herein before the plow structure of the machine.[0062]
FIG. 31 is a schematic diagram showing the components of another alternative embodiment of the present invention being fed into a machine suitable for adaptation to perform the process and make at least one of the products disclosed herein before the plow structure of the machine.[0063]
FIG. 32 is a schematic top plan, view illustrating at least one method by which the components of the alternative embodiment disclosed in FIG. 30 are introduced prior to the plow mechanism of the form fill and seal machine.[0064]
FIG. 33 is a schematic top plan view illustrating at least one method by which the components of the alternative embodiment disclosed in FIG. 31 are introduced prior to the plow mechanism of the form fill and seal machine.[0065]
FIG. 34 is a perspective view generally showing the general relationship of the components for making the various embodiments disclosed herein. Specifically, the embodiment having the peel seal tape is disclosed although after review of this disclosure it will be apparent to a person of ordinary skill in the art how the machinery may be modified to produce the various embodiments disclosed, described, and claimed herein.[0066]
FIG. 35 is side elevational schematic view illustrating the steps of construction of the alternative embodiment disclosed in FIG. 30 subsequent to folding the parent film on the plow structure.[0067]
FIG. 36 is side elevational schematic view illustrating the steps of construction of the alternative embodiment disclosed in FIG. 31 subsequent to folding the parent film on the plow structure.[0068]
FIG. 37 is an alternative embodiment of the present invention illustrating various features of the invention including the use of tear string and a diamond shaped opening as opposed to a circular opening for assisting in the removal of the hood and exposing the zipper assembly.[0069]
FIG. 38 is a schematic diagram showing the components of another alternative embodiment of the present invention being fed into a machine suitable for adaptation to perform the process and make the product disclosed herein, wherein either a tear string or the zipper assembly are introduced to the parent film after the plow.[0070]
FIG. 39 is a side elevational schematic view illustrating the steps of construction of the alternative embodiment disclosed in FIG. 38 wherein the tear string or slider or zipper assembly is introduced after the plow structure.[0071]
FIG. 40 is a front plan view of an alternative embodiment of the present invention.[0072]
FIG. 40[0073]ais a front plan view of the alternative embodiment of FIG. 40, but showing a peel seal area.
FIG. 41 is a view taken from line[0074]41-41 of FIG. 40aand showing the reclosable fastener structure extending over the fold structure and peel seal.
FIG. 41[0075]ais an enlarged view of the structure shown in FIG. 41 and showing the position of the slider or zipper structure over the fold structure relative to the predetermined position of the areas of structured weakness.
DETAILED DESCRIPTIONAlthough the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures or methods. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.[0076]
The present invention is both a method and a structure resulting from the method. The present invention generally relates to reclosable[0077]plastic bags100 and, more particularly, to a reclosableplastic bags100 having a slider orzipper assembly20, which cooperates with a tamper-evident feature. The tamper-evident feature may also be a hermetic seal feature. The method of the present invention, while unique and fully described herein, may be used on known machinery such as, by way of illustration and not by way of limitation, therpm 100 packaging machine manufactured by Klockner Packaging Machinery of Sarasota, Fla., U.S.A. The modifications necessary to the machinery used to practice the present invention will be apparent to a person of ordinary skill in the art after reading this disclosure.
Reclosable plastic bags using various zippers and sealing mechanisms are well known. However, the advantages of the present invention are believed not to be apparent from the known zippers and sealing mechanism of the prior art. The[0078]zipper assembly20 typically includes azipper structure20aand anintegral skirt16. In the present invention, theskirt16 is bonded to theparent film10 at apredetermined seal location14. See FIG. 3.
Referring to FIGS.[0079]1-5, the method and structure of the present invention may begin to be generally described. Referring to FIG. 1 a predetermined portion of theparent film10 is illustrated. Theparent film10, at predetermined locations, is structurally weakened, e.g., by the use of presently known laser scoring technology.
Referring to FIG. 2, an elevational edge view of the[0080]parent film10 including the score lines12 may be seen. The weakenedarea12 may also be imperforate and hermetic. The weakenedareas12 define an integral tear off portion or foldstructure11.
Referring to FIG. 3, the[0081]film10 is folded over, as shown, to form thefold structure11 and azipper assembly20 is inserted. Weakenedareas12 are preferably positioned below thezipper structure20aso that when fold structure orhood11 is removed thezipper structure20ais exposed sufficiently above the resultingfin structures19 to allow the user access to thezipper structure20a. Zipper skirts16 are shown bonded to thefilm10. However, it is presently believed preferable, prior to insertion of thezipper assembly20, that the uncut ends23 (see FIG. 5) of eachzipper assembly20 be punched out or cut to form aradiused notch22a, as shown in FIG. 7. The cut zipper assembly ends22 are sealed together (the sealedmass22bof FIG. 7) which will later function to retain the contents of thebag100 such as food.
Referring back to FIG. 3, the skirt(s)[0082]16 remain intact so that thezipper assembly20 is kept continuous for ease of handling. Once inserted the skirt(s)16 of thezipper assembly20 is bonded to theinside surface10aof theparent film10 at seal location(s)14.
Next sides[0083]30 and32 are sealed, alongmargin10cillustrated in FIGS.5 or7, using a known mechanism such as a heat-sealing bar of a form fill and seal machine by advancing the foldedfilm10 to the heat sealing bar portion of the machine used; creating aseal30aacross the length and width ofmargin10c. The resultingbag100 is then filled with a predetermined foodstuff or other desired material through theopening33 located, opposite thezipper assembly20, atbottom edge34 shown in FIGS.5 or7. Thenbottom edge34 is subsequently sealed, formingseal34a.
This results in the[0084]zipper assembly20 being hermetically sealed within the tear offportion11. Tear offportion11 is integral to theparent film10. Integral tear offportion11 may be easily removed by tearing along the score lines12, leaving thezipper structure20afully exposed and easily accessible for the use desired.
The above noted process and mechanism may also be performed so that the[0085]zipper assembly20 is located along one of thelong sides30 or32 of thebag100 rather than the short side of the rectangle, which is defined by thebag100.
Referring to FIG. 5, a second embodiment of the[0086]present invention1 is illustrated. As may be seen from FIG. 5 twobags100 are shown prior to their being separated alongseam101. This embodiment includesscore lines12 laid out in an alternative pattern that includes curve orarcuate section13 and tearnotch24. As further disclosed in FIG. 7 theparent film10 is sealed atsection26 to either its opposingsides35 and36 or the structure of thezipper assembly20. Thetear notch24 provides a starting point for removing thefold structure11, which is located above thezipper assembly20. Thefold structure11 being defined by the location of the score lines12. The score lines12 extending alongcurve13 to a predetermined area below thezipper assembly20 for substantially the entire width of thereclosable bag100 facilitating removal of the hood or foldstructure11 and exposure of thezipper structure20a. The embodiment of FIG. 5 further including ahermetic seal40.
Referring now to FIG. 8, a cross-sectional view of the embodiment of FIG. 7 may be seen. In particular, the[0087]integral skirt16, usually comprised of two strips on pieces of plastic film or a one-piece unit of continuous film, may be seen to have itsoutside surface19 sealed hermetically to the inside surfaces36aand35aat respectivehermetic seals40aand40. Additionally, apeelable seal50 is located at the bottom of theskirt16. Any standard commercially known resealable adhesive51 may be used to make thepeel seal50. Thepeel seal50 may also be ahermetic seal40b.
Referring now to FIG. 9 an alternative to the embodiment of FIG. 8 is shown. In this embodiment the[0088]zipper skirt16 is heat sealed to theside panels36 and35 respectively of theparent film10. The inside surfaces17 of thezipper skirt16 are peelable sealed to one another, using a known releasable adhesive51, to provide a releasable hermetic or gastight seal50 therebetween. It should be noted that the term's resealable adhesive or releasable adhesive as used herein should be construed interchangeably as well as given their common meaning.
Referring now to FIG. 10 another alternative embodiment of FIG. 8 is shown. In this embodiment the[0089]parent film10 is sealed along apredetermined portion42 ofinside surface35aand36a. A known releasable adhesive51 is used to form apeelable seal50 between inside surfaces35aand36aatpredetermined portion42. U.S. Pat. No. 4,944,409 contains an example of such an adhesive. Presently, CUREX brand grade 4482-0, supplied by Curwood of Oshkosh, Wis. is considered an acceptable adhesive for use with this embodiment of the present invention.
Referring now to FIGS. 11 and 12 another alternative embodiment is illustrated wherein the[0090]peelable seal50 is comprised of apeel seal tape53 having a permanent sealant like a metallocene catalyzed polyethylene located on one side and a releasable seal material like the aforesaid CUREX brand material on the other side (side54).
One possible method for achieving the structure of FIGS. 11 and 12 is the use of a form fill and seal machine system in which the[0091]peel seal tape53 would be tacked onto a predetermined location of theparent film10 prior to theplow200. (See FIGS. 31, 33, and34 for a general illustration of the location of theplow200 in relationship to the other components of a form fill and seal machine. Please note with reference to FIG. 33 that it is presently believed preferable forheat sealer bar208 to be enlarged sufficiently so that in addition to sealing thetear tape120 is place it also seals the permanent seal side of thepeal seal tape53 in place at the same time. Accordingly, while onesealer bar208 is believed preferable for these separate functions multiple bars could be used, each having a dedicated function or a combination of functions). After theplow200 thepeelable sealant side54 would be sealed to theparent film10 by heat sealer bars55. Use of sealer bars208 and55 as disclosed herein allows independent temperatures and pressures to be used for each seal and it is believed that more consistent peel seals will result.
Additionally, the[0092]zipper skirt16 may be sealed in place subsequent to theplow200 bysealer bar56 and theheader seal206amay be made bysealer bar57 as illustrated generally in FIGS. 34 and 36.
Referring now to FIG. 13 another alternative embodiment of FIG. 10 is shown. In this embodiment, the[0093]zipper skirt16 includes anelongated section16a.End21 ofelongated section16ais positioned between the inside surfaces36aand35aof theside panels36 and35 of theparent film10. Theelongated section16ais heat sealed to theparent film10 oninside surface35aand peelable sealed using a known releasable adhesive51 toinside surface36ato formpeel seal50.
Referring now to FIG. 14 a third embodiment of the present invention is disclosed. Again, two[0094]bags100 are shown prior to their being separated alongseam101. The invention of the third embodiment is comprised ofparent film10, which is used to form thebag100 that is to be filled. Thebag100 includes afirst side seal30, asecond side seal32, and afill opening33.Side panel35 forms the front side of thebag100. Thefill opening33, after thebag100 is formed and filled with a predetermined type of food material, is heat sealed to form bottom edge orseal34. Thebag100 further includes afold structure11,header15,integral zipper skirt16, azipper assembly20 including azipper structure20a, at least onehermetic seal40, an unsealedarea60, and asection62 where thezipper skirt16 and theends23 of thezipper assembly20 are heat sealed together (see sealedmass23bin FIG. 14) prior to their insertion between thefront side35 and theback side36 of thefilm10. This forms sealedmass23b. The formation of sealedmass23bmay take place atsealer216, which is illustrated in FIG. 30.
Sealing zipper skirt(s)[0095]16 to theparent film10 forms the hermetic or gastight seal40. The zipper skirts16 may have a predetermined portion or portions that extendpast seal40 and which may be held together with apeel seal50. See for example, FIG. 15.
Since, within the unsealed[0096]area60, theside panels35 and36 are not attached to thezipper assembly20, the hood structure11 (which may be defined by the score lines12) may be easily removed to exposezipper structure20a. The sealedmass23bprovides for containment of product when thepeelable seal50 is opened.
Referring to FIG. 15 a view from[0097]line15--15 of FIG. 14 may be seen. This may be seen to be identical to the embodiment of FIG. 8, except as explained above with reference to FIG. 14.
Referring now to FIG. 16 an alternative structure to the one shown in FIG. 15 may be seen. In this alternative, the[0098]zipper skirt16 is made of one piece of material. It is heat sealed to the inside surfaces35aand36ato formhermetic seals40 and40a. Theskirt16 is provided with astructural weakness45 which extends linearly and generally parallel tohermetic seals40 and40aalong thezipper skirt16. Thestructural weakness45 is designed to fracture or tear relatively easily when the customer opens thebag100.
Referring now to FIG. 17, an alternative to the embodiment shown in FIG. 16 may be seen. In this embodiment the[0099]zipper skirt16 includes abarrier film section16b. Thebarrier film16bis applied (preferably by heat sealing although other methods could be used, e.g., Adhesive coupling, ultrasonic or high frequency sealing technology) to theinside surface16dof thezipper skirt16. Thezipper skirt16 is heat sealed along a predetermined portion of itsoutside surface16etoparent film10 to form ahermetic seal40. Thebarrier film section16bis releasably sealed to theinside surface16dto form at least onepeel type seal50. Note that it is presently believed thatsection16bmust have asurface16cthat is resistant to heat sealing.
Referring now to FIG. 18 an alternative to the embodiment shown in FIG. 17 may be seen. In this embodiment[0100]barrier film section16bis heat sealed to a separate predetermined portion of the inside surfaces35aand36aof theparent film10. To form two additionalhermetic seals40 located below thehermetic seals40 of thezipper skirt16. Thebarrier film16bis provided with a structural weakness at45 which extends linearly and generally parallel tohermetic seals40. The structural weakness is designed to fracture or tear relatively easily when the customer opens thebag100.
Alternatively, the structure of FIG. 17 could be provided with a structural weakness,[0101]45 as described with reference to FIG. 18. In such acase peel seal50 would be replaced with a permanent seal.
Referring to FIGS. 19 and 20,[0102]header strip206, located between thefront side35 and backside36 of theparent film material10, of a predetermined size have sufficient width to extend down to, preferably just above, a tear line132 (area of structural weakness). Theheader strip206 terminates at edge(s)131. Thistear line132 has the predetermined propensity to tear in predetermined way. The extension of theheader strip material206 extends down so that it is adjacent to thetear line132. This facilitates tearing off thehood structure11 from thebag100 along thetear line132. Theoptional tear notch134 facilitates initiation of the tear, the tear line132 (the orientedparent film10 orfilm10 with the propensity to tear) directs the tear, and theheader material206, which is bonded or sealed to thefront side35 and backside36 of theparent film10, controls the tear so that thezipper structure20ais consistently clear of theparent film material10 after the removal of thehood structure11.
Alternatively, if the[0103]header material206 is made of an oriented polypropylene having at least one side with a heat sealable sealant then theparent film10 would not need to be oriented or have thetear line132 or propensity to tear. Presently, it is believed preferable that if theheader material206 is made of an oriented polypropylene then the oriented polypropylene should have both its sides coated with a heat sealable sealant. Also, alternatively, a plurality of header strips206 could be used instead of a singleintegral header strip206. In either case, theparent film10 would not necessarily need to be oriented or have atear line132 or a propensity to tear.
Referring to FIGS. 21 and 22, at least one but preferably two pieces of[0104]tear tape120, located between thefront side35 and backside36 of theparent film material10 on film surfaces35aand36a, of a predetermined size are bonded or sealed to theparent film10 of thehood structure11 adjacent, preferably just above, a tear line132 (area of structural weakness). Thistear line132 has the predetermined propensity to tear in predetermined way. Thetear tape material120 adjacent thetear line132 facilitates tearing off thehood structure11 from thebag100 along thetear line132 in a controlled manner. Theoptional tear notch134 facilitates initiation of the tear, the tear line132 (the oriented parent film or film with the propensity to tear) directs the tear, and thetear tape120, which is bonded or sealed to thefront side35 and backside36 of theparent film10, controls the tear so that thezipper structure20ais consistently clear of theparent film material10 after the removal of thehood structure11. Alternatively, if thetear tape material120 is made of an oriented polypropylene having at least one side with a heat sealable sealant then theparent film10 would not necessarily need to be oriented or have thetear line132 or propensity to tear.
With respect to facilitating removal of hood or fold[0105]11 it should be understood that instead ofscore lines12 theparent film10 may be weakened in predetermined areas using other procedures as well, including but not limited to scoring or the use of multiply laminate film having a predetermined weakened area or the addition of a tear assistance structure, e.g.,Tear tape120 ortear string120a. The tear assistance structure may be added for use by itself or in conjunction with a predetermined area ofstructural weakness12 to aid in the tearing of thefilm10. See FIGS. 28 and 29.
Referring to FIG. 23 another alternative to the embodiment disclosed in FIG. 22 is disclosed. In this[0106]embodiment tear tape120 is applied to both the inside surfaces36aand35aand theoutside surfaces36 and35 of thebag100. In this embodiment no score line or weakening132 is believed necessary (although such an area of structural weakness could be used) since thetear tape120 located on both the inside and outside surfaces of thebag100 will act as an effective tear guide.
Referring to FIGS. 24, 25, and[0107]26 another alternative to the embodiment shown in FIG. 22 is illustrated. In this embodiment a modifiedtear tape120bhaving atear bead120cis used.
As FIGS.[0108]24-26 illustrate, when thefilm10 is sealed to thetear tape120bthebead120cis depressed into thefilm10 creating an area ofstructural weakness12 without requiring prescoring or other modification of theparent film10 prior to the application of thetear tape120b. This structure is believed beneficial because thetear tape120bis always in alignment with the area ofstructural weakness12.
Referring to FIG. 27 another alternative to the embodiment disclosed in FIG. 22 is disclosed. In this[0109]embodiment tear tape120 is applied to both the inside surfaces36aand35aand theoutside surfaces36 and35 of thebag100. Thetear tape120 is applied to border both sides of the score line orweakening132. Since thetear tape120 is located on both sides of thescore line132 and on the inside and outside surfaces of the bag100 a very consistent controlled or guided will be achieved.
[0110]Tear tape120 is interchangeable withtear string120a. Accordingly, atear string120acould be substituted for thetear tape120. See, e.g., FIGS.38 and39. Preferably, thetear tape120 or thetear string120aused is made from a material, e.g., Thermoplastic material, that is compatible with thefilm10 and which may be sealed, coupled, or bonded to thefilm10. For example, thetear tape120 ortear string120amay be formed of polyethylene or may be encased in polyethylene. It is understood in the art that a tear string, such astear string120a, may have various cross-sectional shapes, e.g., Round, square, triangular, etc., which may be used to enhance its ability to tear theparent film material10.
In particular, referring to FIGS. 30, 32, and[0111]35, the process by which the alternative embodiment havingtear tape120 is presently believed to be manufacturable is illustrated using anrpm 100 machine. Theparent film10 is fed over a predetermined number of rollers and toward theplow structure200. Theparent film10 after passing overdancer roller203ais die punched bydie210 to presentparallel openings121. It is presently believed that thefilm10 must pass over thedancer rollers203aso that they are kept sufficiently taught thus allowingopenings121 to be punched out accurately at predetermined positions, bydie210, such that the positions of theopenings121 are always at the same or a uniform distance from each other. In addition to theparent film10 two rolls oftear tape120 are feed over theparent film10 and in parallel alignment with theparallel openings121 such that thetear tape120 preferably, but not necessarily, bisects each theparallel opening121.Tear string120acould be substituted fortear tape120. See, e.g., FIGS. 38 and 39.
In addition, referring back to FIGS. 30, 32, and[0112]35, optionally aheader material206 may be fed over theparent film10. Further, the zipper orslider assembly20 is also fed over theparent film10. Prior to being fed over theparent film10 thezipper assembly20 has anotch22adie punched, bydie214 and heat sealed bysealer216, at a predetermined position that is also designed to be in general alignment with theparallel openings121. Once thetear tape120 is presented over theparent film10 but before it is passed over theplow200 it passes over a teartape sealer mechanism208 so that thetear tape120 is sealed to theparent film10. Alternatively, thetear tape120 could be tacked in place and subsequently sealed to theparent film10 either before or after theplow200.
The[0113]parallel openings121 may be of any shape although circular is the shape that is presently preferred. Diamond shaped cuts could be used to further enhance initiation of the tear in theparent film10. See FIG. 37.
Additionally, the[0114]notch22aas generally illustrated herein may be of an arcuate or radiused shape but thenotch22acould also be made at a sharp angle such as a 90° angle. See FIG. 37. The sharper angle is presently believed to add more stress to the structure of thezipper assembly20 and therefore a radiused structure is presently considered to be preferred. However, the present invention should not be interpreted as being limited to solely aradiused notch22aas generally illustrated herein.
After the[0115]parent film10 is folded the remaining manufacturing process is carried out as generally illustrated in FIG. 35. The zipper skirts16 are sealed to the respective sides of theparent film10 atseal14. Theheader strip206, if used, is sealed to theparent film10 atseal206a. Theside seal30ais made, which also seals the perimeter or edge121aofopening121. (note, if notear tape120 ortear string120ais used then it is presently considered best to add atear notch24 to theopening121 to facilitate removal of thehood11.) Anopening123 is die punched in thepackage100 to provide a point where thepackage100 may be easily hung for display purposes. Thepackage100 is then cut alongseam101 from the V-fold portion of the form fill and seal machine and transferred to the fill and seal stations wherefill opening33 is opened and thepackage100 is filled and gas is flushed through thefill opening33.Opening33 is then hermetically sealed atseal34a.
Alternatively, referring to FIG. 38 and FIG. 39 the[0116]zipper assembly20 may be introduced subsequent to theplow structure200. Theparent film10, prior to being fed over therollers202 is still die punched bydie210 to presentparallel openings121. Also, alternatively, thetear tape120 ortear string120amay be feed over theparent film10 and in parallel alignment with theparallel openings121 subsequent to theplow200. See FIGS. 38 and 39. Again, thetear tape120 ortear string120apreferably, but not necessarily, bisects eachparallel opening121. Also, while FIG. 39 shows both thetear string120aand skirts16 of thezipper assembly20 being introduced to theparent film10 subsequent to theplow200 and respectively sealed bysealer bars208 and209 it should be understood that either thetear string120aor thezipper assembly20 could be introduced before theplow200. For example, thezipper assembly20 could be introduced after theplow200 and thetear string120aprior to theplow200. Sincetear tape120 is interchangeable with thetear string120ait will be apparent to a person of ordinary skill in the art reading this disclosure that thetear tape120 could also be introduced after theplow200 and used in essentially the same manner as thetear string120a.
The[0117]openings121 are provided, at a minimum, to facilitate access to thetear tape120 or thetear string120aand to facilitate tearing and removal of thehood11 to expose thezipper assembly20.
Additionally, the present invention may be used in combination with other VFFS and HFFS machines. The present invention could also be used with HFW machines. However, in using either VFFS machines or HFFS machines the method of the present invention is presently believed to require post-compression (commonly called post-squashing) of a predetermined portion of the[0118]track structures20b, with respect to the embodiment shown in FIG. 6. (sometimes also referred to astrack mass20b, herein) of theslider closure assembly20 located within a margin orline10bof theparent film10 where aseal30a, especially a hermetic seal, is desired. Alternatively, thetrack mass20bmay have a pre-compressed portion located withmargin10b. Neither pre-compression nor post-compression are believed to be required where a notch, e.g.,22aof FIG. 7, has been punched out or cut from thezipper assembly20. However, if pre-compression is desired then this is accomplished in the present invention atsealer216 shown in FIG. 30. This is so that when, on either a HFFS or VFFS machine, thetrack mass20b(with the slider orzipper structure20aavoided) passes through the package side seal zone portion of either the machine a consistenthermetic seal30ais produced by the application of the heater bars of the machine used. As will be apparent to a person of ordinary skill in the art from this disclosure, if a notch, e.g., notch22aof FIG. 7, is cut from thezipper assembly20 then there is no structure or mass forsealer216 to pre-compress andsealer216 will then only provideseal22bof thecut end22, as shown in FIG. 7.
In applications using HFW machines for the manufacture of the embodiment shown in FIG. 5, such as Jones Automation Company machines, it is not believed necessary to pre-compress, post-compress, or squash a predetermined portion of the[0119]track mass20b. HFW machines have a rotary jaw assembly, which includes a hinged side. The jaw assembly provides at least two advantages, either of which, separately or in combination, eliminates the need for pre-compression of thetrack mass20b. First, the jaw assembly provides a relatively long time, longer than the time provided by either VFFS or HFFS machines, for the application of heat and pressure sufficient to form the desiredseal30a. Second, the portion of thetrack mass20bthat is targeted to be fused or sealed (generally located within the boundary of margin lob) is placed or fed into the jaw assembly so that it is placed toward and near the hinged portion of the jaw assembly and thus maximum mechanical advantage and force may be applied to the predetermined portion of thetrack mass20b.
If either the longer seal time or the mechanical advantage of the jaw assembly of the HFW machine was not available then, referring to FIG. 6, since there is generally insufficient room on an HFW machine to pre-compress the[0120]track mass20b, thetrack mass20bmay be pre-punched with a die at thepredetermined location22a(where theseal30ais also to be applied or created) prior to insertion into thefold11 of theparent film10. Since the pre-punched area or notch22awould be synchronized to be in registration with the portion of the foldedparent film10 that is to be sealed, less energy (time, temperature, and/or pressure), due to the reduced mass to be sealed is required to consistently obtain the type ofseal30adesired. (note, pre-punching rather than pre-compression could also be used with HFFS or VFFS machines.) Referring now to FIGS. 40, 40a,41 and41a, an alternate embodiment of the present invention may be seen. Thefilm10 is folded over, as shown, to form thefold structure11, and azipper assembly20 is positioned over thefold structure11. Weakenedareas12 are preferably positioned below thezipper structure20a, so that when thezipper structure20ais in the open position thefold structure11 and its weakenedareas12 are exposed to allow the user access to thefold structure11. Seen particularly in FIG. 41, the overlayingzipper skirt16, of the alternate embodiment may be viewed.Zipper skirt16 is usually comprised of two strips of pieces of plastic film or a one-piece unit of continuous film, and is seen to have itsinside surfaces17 sealed hermetically to theoutside surfaces35b,36bof thefilm10 at respectivehermetic seals40c,40d. Thefold structure11 is preferably designed to act as an imperforate hermetic barrier to protect the contents ofbag100. Tearing thefold structure11 allows the user access to the contents and also provides visual evidence that the hermetic seal is broken. Seen particularly in FIGS. 40aand41, the inside surfaces35a,36aof theparent film10 may also be peelably sealed to one another, using a known releasable adhesive51, to provide a releasable hermetic or gastight seal50 therebetween. Theseal50 is located adjacent, perferably just below, the weakenedareas12.
As best seen in FIGS. 40 and 40[0121]a, twobags100 are shown prior to their being separated alongseam101. The alternate embodiment seen in these views is comprised ofparent film10, which is used to form thebag100 to be filled. Thebag100 further includes aheader15, and apeg hole15a, seen in this embodiment at the end opposite thefold11. It is presently believed preferable, after the folding and sealing ofparent film10 that theparent film10 be punched out to form atear area24a. The parent film is then sealed around the perimeter of the punched outtear area24aand atear notch24 is added, as seen in FIG. 40. These steps are preferably performed before the attachment of thezipper assembly20 and zipper skirt(s)16. Following this, thezipper assembly20 is positioned and bonded to theoutside surfaces35b,36b, of theparent film10, and over thefold11. Alternately, theparent film10 may be sealed around the perimeter to include the sealed perimeter of the punched outtear area24aso that after the punching step which forms teararea24a, the sealed perimeter remains. Thetear notch24 provides a starting point for removing thefold structure11, which is surrounded by thezipper assembly20 and attachedzipper skirt16. Further, at least one piece oftear tape120, located between thefront side35 and backside36 of theparent film10 on film surfaces35a,36a, of a predetermined size may be bonded or sealed to theparent film10 at thefold11. Thetear tape120 is located adjacent, preferably just above, a tear line132 (area of structural weakness). Thistear line132 has the predetermined propensity to tear in a predetermined way. Thetear tape material120 adjacent thetear line132 facilitates tearing off thefold structure11 from thebag100. Theaforementioned tear notch24 facilitated initiation of the tear.
Referring to FIGS. 41 and 41[0122]a, the skirt(s)16 remain intact so that thezipper assembly20 is kept continuous for ease of handling. Once positioned over the punchedfold structure11, the skirt(s)16 of thezipper assembly20 is bonded to theoutside surfaces35b,36bof theparent film10 at seal location(s)40c,40d. Next, sides30 and32 are sealed, alongmargin10cillustrated in FIG. 40, using a known mechanism such as a heatsealing bar of a form fill and seal machine (as described earlier in the present application) by advancing thefilm10 to the heat sealing bar portion of the machine to be used.
It will be apparent to the person of ordinary skill in the art after reading this disclosure that the present alternate embodiment shown in FIGS. 40, 40[0123]a, and41,41amay be manufactured using the methodology previously disclosed herein with the necessary modifications, which this specification makes apparent to a person of skill in the art.
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described.[0124]